Mine roof supports



July 16, 1968 J. w. BELL MINE ROOF SUPPORTS 3 Sheets-Sheet 1 Filed Dec. 20, 1965 INVENTOR:

BELL

BY a M A't'rs.

J'Ack w.

July 16, 1968 J W. BELL 3,392,533

MINE ROOF SUPPORTS Filed Dec. 20, 1965 5 Sheets-$heet 2 JACK W- BELL av M INVENTOR:

y 6, 1968 J. w. BELL 3,392,533

I ROOF SUPPORTS Filed Dec. 20, 1965 5 Sheets-Sheet 5 79b 0 FIG 3.

INVENTOR:

United States Patent 3,392,533 MINE ROOF SUPPORTS Jack Wallwork Bell, Bolton, England, assignor to Gullick Limited, Wigan, Lancashire, England, a British company Filed Dec. 20, 1965, Ser. No. 514,830 Claims priority, applicatigal /G6r5eat Britain, Jan. 6, 1965, 4 Claims. (CI. 61-45) ABSTRACT OF THE DISCLOSURE A self-advancing mine roof support comprising two prop units spaced apart one behind the other and each having a base plate mounting prop means. The base plate of the forward unit is pivotally connected in closely spaced relation to the base plate of the rear unit and at least one pressure-fluid extensible prop is pivotally mounted, for angular movement towards and away from a mineral face, on the forward part of the base of the forward unit. Thus, when said pressure-fluid extensible prop is extended into roof-supporting condition, it is operative to force the base of the forward unit against said floor to prevent the floor lifting between the base of the rearward unit and the base of the forward unit.

This invention is for improvements in or relating to self-advancing or powered mine roof supports.

The invention is particularly, although not necessarily exclusively, concerned with improvements in, or modifications of, the roof support described in the specification of United States Patent No. 3,197,966.

In that specification there is described a self-advancing roof support comprising at least two roof-supporting units or elements arranged in tandem and a roof-bar supported by and between upper parts of said supporting units or elements, wherein the two units or elements are articulated or pivotally linked together at their lower parts and wherein a pressure-fluid ram device for advancing the support has one of its members secured to one unit or element and its other member adapted for connection to an anchorage other than a part of the support. In one preferred embodiment of this support one roof support unit or element has a plurality of legs or props and the other unit or element has a single leg or prop. The roofbar has a beam part supported on and between the upper parts of said plurality of legs or props and a cantilever part supported by an upper part of the single leg or prop. Conveniently the beam part and the cantilever part of the roof-bar structure are articulated or pivoted together.

Under certain mining conditions the floor is subject to lifting which is due to stress relieving of the geological strata caused by the removal of the coal or other mineral. This condition is also sometimes prominent where the floor is subjected to water and the absorption of the water by the floor causes swelling.

In mine roof supports comprising a rear unit or element and a forward unit or element as constructed heretofore, there is a space, at floor level, between the base of the rear unit and the base of the forward unit and it is in this space that the floor material builds up due to the just-mentioned lifting of the floor. This restricts operation of the pressure-fluid ram incorporated in the support to advance the support and also, in some cases, push over the conveyor towards the coal face. This lifting of the floor also restricts or interferes with movement of the linkage or articulating arrangement between the base of the rear unit and the base of the forward unit and damage thereto may well result.

An object of the present invention is to provide a 3,392,533 Patented July 16, 1968 self-advancing, i.e. powered, support in which this is avoided.

A further object of the invention is to provide improvements in, or modifications of, the support described and claimed in United States Patent No. 3,197,966.

Brief summary of the invention According to the present invention there is provided a self-advancing mine roof support comprising two roofsupporting prop units, spaced apart one behind the other, the forward unit having a rigid plate-like base having an area sufiicient to cover a substantial portion of floor space between the rear unit and said forward unit, pivot means pivotally connecting the rear of said plate-like base to the rear unit, and at least one pressure-fluid extensible prop pivotally mounted, for angular movement towards and away from a mineral face, on the forward part of said plate-like base whereby, when extended into roof-supporting condition, it is operative to force said plate-like base against said floor to prevent lifting of said floor between the rear unit and the forward unit.

A pressure-fluid ram which, in known manner, is provided for advancing the support by connection of the ram to a coal-face conveyor has an extension bar for said connection and said extension bar is relatively fiat and wide as compared to the piston rod of the ram. Conveniently said extension bar is slidably positioned on the plate-like base of the forward support unit.

One particular embodiment of the invention will now be described, by way of example, as applied to a mine roof support similar, in several respects, to that described and claimed in the specification of United States Patent No. 3,197,966. In the following description reference is made to the accompanying semi-diagrammatic drawings in which:

FIGURE 1 is a side elevation of the support,

FIGURE 2 is a plan view of the support with a part of the roof-bar structure broken away,

FIGURE 3 is a fragmentary sectional view on the line IIIIII of FIGURE 2,

FIGURE 4 is a fragmentary sectional elevation on the line IVIV of FIGURE 2,

FIGURE 5 is a fragmentary side elevation of a modification of the construction shown in FIGURES 1, 2 and 3, and

FIGURE 6 is a fragmentary sectional view on the line VI-VI of FIGURE 5.

Briefly, the support shown in FIGURES 1, 2, 3 and 4 comprises a rear unit 10 and a front unit 11.

The rear unit 10 comprises a base 12 in which are mounted, in rectangular formation, four hydraulically extensible telescopic props or legs 13, only two of which are visible in the drawings. These props or legs support on their upper ends in the usual way a roof-bar structure or canopy 14.

Housed in the base structure of the rear unit is a double-acting hydraulic ram 15, the piston rod 15a of which is pivotally connected by an extension member or relay bar 16 and a clevis 17 to a bracket or spill-plate 18 on the conveyor C.

The front unit comprises a base 19 having an arch or pedestal-like part 1% on which is pivotally mounted at 20 a single hydraulically extensible telescopic prop or leg 21. Angular movement of the leg 21 about the pivot 20, in the vertical plane towards and away from the coal face, is controlled by a coiled spring 22. Pivotal mounting of the leg 20 is necessary to permit the support to adjust to various configurations of the floor and roof and at the same time lend stability.

At its upper part the leg or prop 21 supports in the usual way a cantilever roof-bar 23 pivotally or hingedly attached to the roof-bar structure or canopy 14 at 24.

Concave-convex pivotal seatings 14a and 23a are provided where the roof-bars 14 and 23 rest on the props 13 and 21.

The supply of hydraulic pressure-fluid to the props 13 and 21 and to the ram 15 is controlled by a manually operable valve 15a. The arrangement is such that first hydraulic pressure is supplied to the ram so as to extend it and push the conveyor C towards the coal face newly exposed by the passage of the coal winning machine, then the pressure in the props is relieved, so that the support is freed from between floor and roof, and the ram 15 is retracted so as to advance the support towards the face and finally the props are again extended so as to re-set the support.

For the purpose of the present invention the base ,member 19 of the forward unit is extended rearwardly as indicated at 19a and is pivotally or hingedly attached to the rear unit as indicated at 25. Furthermore, as can be seen from FIGURES 2 and 3, the member 19, 19a is relatively wide and flat (i.e. tray-like) and serves to cover the floor space which has heretofore existed between the base of the rear unit and the base of the forward unit. Thus, lifting of the floor in this space is at least materially restricted. Furthermore, crawling through the travelling track T by workers at the coal face is made easier.

It will be appreciated that when a series of supports are positioned in line the base members 19, 19a of neighbouring supports will lie fairly close together to cover a substantial area of the floor.

Preferably the rearward extension 19a of the base 19 is integral with said base but it could, for example, be a separate part rigidly bolted to the base 19.

The relay bar 16, which operates freely through the base or arch part 19b of the base of the forward unit, as described in United States patent specification No. 3,197,- 966, is also relatively flat and low set (e.g. slides on the base member 19) so as not to obstruct the travelling track and also to make it more easy to crawl therealong. It will be noted that the base member 19 has upstanding side rims and the extension bar 16 is located below the upper edges of these shallow rims.

In the modified arrangement shown in FIGURES and 6 an arch-like mounting unit 26 for the front leg or prop 21 straddles the relay bar 16, which passes freely through it, and is pivotally attached to upstanding lugs or brackets 27 on the base member 19, 19a. Apart from this modification the support may be similar to that described with reference to FIGURES 1, 2, 3 and 4 and spring means may be provided for controlling angular movement of the prop.

The manner in which the support unit above described is operated is described more fully in United States patent specification No. 3,197,966.

The rear unit may comprise a single leg or two, three,

four or more legs and similarly the front unit instead of comprising only one leg may have two, three, four or more legs. Generally, in the case of the forward unit, if there is more than one leg the legs will 'be arranged in side-by-side relationship, i.e. in the direction of length of the coal face.

I claim:

1. A self-advancing mine roof support comprising two roof-supporting prop units spaced apart one behind the other, the rear unit having a plate-like base and prop means thereon for supporting a mine roof, the forward unit having a rigid plate-like base having a rear edge disposed in close adjacency to the forward edge of said base of the rear unit, pivot means pivotally connecting said rear edge of the forward unit to the rear unit, and at least one pressure-fluid extensible prop pivotally mounted, for angular movement towards and away from a mineral face, on the forward part of said plate-like base of the forward unit whereby, when extended into roof-supporting condition, it is operative to force said plate-like base of the forward unit against said floor to prevent lifting of said floor between the rear unit and the forward unit.

2. A self-advancing mine roof support as claimed in claim 1 wherein the pressure-fluid extensible prop of the forward unit is pivotally mounted on the plate-like base of the forward support unit, for movement towards and away from a mineral face, by a horizontal pivot pin, a spiral spring encircling said pivot pin and having limbs which engage respectively with said plate-like base and the pressure-fluid extensible prop to control said angular movement of the prop.

3. A self-advancing mine roof support as claimed in claim 1 wherein a pressure-fluid ram for advancing the support by connection of the ram to a conveyor has an extension bar for connecting it to said conveyor and said extension bar is relatively fiat and wide, as compared to a piston rod of said ram, and is slidably positioned on the plate-like base of the forward support unit.

4. A self-advancing mine roof support as claimed in claim 3 wherein the pressure-fluid extensible prop of the forward support unit is pivotally mounted on the upper part of an arch on the forward part of the plate-like base of said forward support unit, the extension bar for connecting the ram to a conveyor passing freely through said arch.

References Cited UNITED STATES PATENTS 2,910,282 10/1959 Barrett 6145.2 3,097,829 7/1963 Seddon 6145.2 3,197,966 8/1965 Arnott 61-45.2 3,201,943 8/1965 Wilkenloh et a1 6145.2 3,216,202 11/1965 Seddon 6145.2 3,270,510 9/1966 Walsh 6145.2

FOREIGN PATENTS 866,108 4/1961 Great Britain. 1,143,771 2/1963 Germany.

DAVID J. WILLIAMOWSKY, Primary Examiner.

D. L. TAYLOR, Assistant Examiner. 

